Piansangsan, Leardpan, Pooncharat Yangnok, and Samran Lertkonsarn. “Development Free Fall Motion teaching aid with Metal Detection sensor”. SciTech Research Journal 7, no. 1 (April 30, 2024): 27–40. accessed September 11, 2026. https://ph02.tci-thaijo.org/index.php/jstrmu/article/view/252147.